首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3213篇
  免费   405篇
  国内免费   59篇
耳鼻咽喉   117篇
儿科学   179篇
妇产科学   163篇
基础医学   292篇
口腔科学   63篇
临床医学   303篇
内科学   577篇
皮肤病学   98篇
神经病学   52篇
特种医学   87篇
外国民族医学   3篇
外科学   578篇
综合类   192篇
预防医学   60篇
眼科学   37篇
药学   67篇
中国医学   9篇
肿瘤学   800篇
  2024年   9篇
  2023年   64篇
  2022年   108篇
  2021年   162篇
  2020年   160篇
  2019年   167篇
  2018年   135篇
  2017年   158篇
  2016年   163篇
  2015年   150篇
  2014年   189篇
  2013年   232篇
  2012年   159篇
  2011年   147篇
  2010年   130篇
  2009年   136篇
  2008年   136篇
  2007年   151篇
  2006年   143篇
  2005年   116篇
  2004年   106篇
  2003年   72篇
  2002年   56篇
  2001年   65篇
  2000年   47篇
  1999年   36篇
  1998年   57篇
  1997年   50篇
  1996年   32篇
  1995年   39篇
  1994年   27篇
  1993年   27篇
  1992年   28篇
  1991年   32篇
  1990年   15篇
  1989年   20篇
  1988年   21篇
  1987年   16篇
  1986年   24篇
  1985年   14篇
  1984年   11篇
  1983年   9篇
  1982年   8篇
  1981年   18篇
  1980年   10篇
  1979年   9篇
  1978年   4篇
  1977年   6篇
  1974年   1篇
  1972年   1篇
排序方式: 共有3677条查询结果,搜索用时 15 毫秒
11.
Methods: Second primary cancers constitute approximately 9–10% of malignancies diagnosed in the United States. We aimed to show the risk and incidance of second primary tumor occuring associated to urologic tumors and show the distrubution of tumors in Tracia region. We retrospectively examined the patients' files with the diagnosis of malignant disease between the years 1985–2000. Hazard function analysis was performed to estimate the relative risk of secondary malignancy occuring. Age, sex and tumor number were examined to find out if they affect on mortality rate. Results: A total number of 25 MPMNs were diagnosed. In 52 percent of the cases the second primary neoplasm developed within six months. The relative risk of development of a second neoplasm is found as increasing 1.111 times per month. The incidence of secondary malignancy occuring in the patients with one tumor was found as 6.31%. Age (p < 0.001) and tumor number (p < 0.001) are found as statistically effective predictor on mortality rate where the sex is not. Conclusions: In the patients with a primary tumor not only the metastasis must be investigated but also second primary tumors should be taken in to consideration. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
12.
AIM: To evaluate the incidence, nature and prognosis of multiple primary malignancies involving renal cell carcinoma (RCC) in Japan. METHODS: Between 1975 and 1998, 319 patients underwent an operation for RCC at Hokkaido University, Sapporo, Japan. The incidence of other primary malignancies was determined and classified as antecedent, synchronous or subsequent. Follow-up was obtained by thorough chart review or telephone interview, and ranged from 0 to 276 months (median 49.0 months). To analyze the influence of other primary malignancies on prognosis, overall and cause-specific survival rates of the patients with an antecedent or synchronous malignancy were compared to the remaining patients. RESULTS: Of the 319 patients there was at least one other malignancy in 38 patients (12%). Four patients had two other malignancies. The other malignancies were antecedent in 13, synchronous in 19 and subsequent in 10 patients. Twenty-two patients had gastrointestinal cancer. In cases of antecedent or synchronous diagnosis of other primary malignancies, RCC was commonly incidental, small or low-stage. Multivariate analysis using Cox's proportional hazards model showed that, for overall survival, the presence of other antecedent or synchronous malignancies was the second most significant prognostic factor, following the pathological stage of RCC. CONCLUSIONS: In Japanese patients with RCC, the incidence of other primary malignancies was not uncommon and these malignancies contributed to the prognosis of these patients. Therefore, the malignant potential of individual tumors should be paid careful attention in the management of these patients.  相似文献   
13.
We examined 161 human tissue samples using the spot hybridization technique with nonradioactive labeled DNA probes of human papillomavirus (HPV). Whole cells were spotted on nitrocellulose filters; DNA of the cells was denatured and fixed to the filter. Then the DNA spots were hybridized to nonradioactive labeled DNA and monitored by a sandwich immunoenzymatic reaction. This technique is simple, sensitive, specific, requires no special equipment, and can be used in clinical settings. HPV DNA was found in 92% of samples in which, on the basis of histologic and colposcopic criteria, its presence was suspected, as well as in 31 samples where it was not suspected.  相似文献   
14.
目的探讨潘南金在急性心肌梗死(AMI)治疗中改善恶性心律失常及心功能的作用。方法将患者随机分为潘南金组及对照组各40例,在AMI常规治疗基础上,潘南金组予潘南金注射液40mL加入5%葡萄糖注射液500mL中静脉点滴,1次/d;同时加服片剂2片/次,3次/d。对照组则予极化液静点,1次/d。2组均在CCU监护1周后转入普通病房,共治疗3~4周。结果恶性心律失常发生率潘南金组为25%,对照组为65%,2组比较P<0.01。出院时心功能NYHA分级改善2级以上者,潘南金组为58%,对照组为45%,2组比较P<0.05。结论对AMI患者尽早应用潘南金治疗,可明显降低恶性心律失常发生率和改善心功能,且不良反应少,可列为常规用药。  相似文献   
15.
本文以自编病前负性情绪调查表、LSE─R及EPQ对56例妇癌住院病人进行了调查,并以56例内科病住院病人作对照。结果显示,69.6%的妇癌病人在病前有负性情绪,而内科病病人只有16.1%;85.7%的妇癌病人病前经历了负性生活事件,而内科病组则为58.9%;EPQ评定结果神经质分亦为前者高于后者,均提示社会心理因素与妇癌的发生密切相关。  相似文献   
16.
Frantz's tumour (papillary and cystic tumour) of the pancreas is a rare neoplasm usually seen in young women. It is of low grade malignancy and deserves special note among pancreatic malignancies as it is frequently amenable to local resection and has a good long-term survival rate after excision. Three such cases have been treated at Westmead Hospital, one young male and two females. In two the disease was confined to the pancreas. In one, local invasion outside the pancreas and trans-coelomic spread to the ovaries was present at the time of diagnosis. Complete surgical removal of macroscopic disease was achieved in all three and all remain disease free between 2 and 4 years post-surgery. All have good exocrine and endocrine pancreatic function. These cases are discussed in detail. The need to be aware of this uncommon variant of pancreatic cancer is stressed. Investigation and treatment options are reviewed. The role of cytology studies in diagnosis and the potential for long-term surgical control of this tumour are highlighted on the basis of our limited experience and that presented in recent surgical literature.  相似文献   
17.
Impaired hepatic function is a major contributory factor to the high incidence of postoperative morbidity and mortality in patients with malignant biliary obstruction. Dynamic hepatic function tests such as indocyanine green (ICG) retention and aminopyrine breath tests were evaluated in such patients to define whether they were clinically useful for prediction of postoperative morbidity and mortality. Forty-four patients with malignant biliary obstruction undergoing surgery for relief of obstructive jaundice were recruited into the study. Indocyanine green retention and aminopyrine breath tests were carried out in all patients pre-operatively and repeated in 36 patients postoperatively. The ICG retention was abnormal in all patients before surgery and there was significant improvement 2 weeks after surgery (32.8 ± 2.5%vs 18.3 ± 2.8%, P= 0.001). The change in ICG retention levels correlated with the serum bilirubin levels but the pre-operative ICG retention value could not predict postoperative morbidity and mortality. The aminopyrine breath test was abnormal in all but one patient. It correlated with pre-operative prothrombin time of the patients before surgery but it did not improve significantly after surgery and was not predictive of postoperative outcome. It is concluded that both ICG retention and aminopyrine breath tests have limited clinical value in the pre-operative evaluation of patients with malignant biliary obstruction.  相似文献   
18.
Transplant recipients have increased cancer risk, but data on risk variation across different patient groups are sparse. Rates and standardized rate ratios (SRR) of cancer (all sites, excluding nonmelanocytic skin and lip cancer) compared to the general population were calculated, using Australia and New Zealand Dialysis and Transplant Registry data. Within the transplant population, risk factors were identified (hazard ratios: HR; 95% CI) and absolute risk estimated for recipient groups. A total of 1642 (10.8%) of 15 183 recipients developed cancer. Risk was inversely related to age (SRR 15-30 children, 2 if >65 years). Females aged 25-29 had rates equivalent to women aged 55-59 from the general population. Age trend for lymphoma, colorectal and breast risk was similar; melanoma showed less variability across ages, prostate showed no risk increase. Within the transplanted population, risk was affected by age differently for each sex (p = 0.007), elevated by prior malignancy (HR 1.40; 1.03-1.89), white race (HR 1.36; 1.12-1.89), but reduced by diabetic end-stage kidney disease (ESKD) (HR 0.67; 0.50-0.89). Cancer rates in kidney recipients are similar to nontransplanted people 20-30 years older, but absolute risk differs across patient groups. Men aged 45-54 surviving 10 years have cancer risks varying from 1 in 13 (non-white, no prior cancer, diabetic ESKD) to 1 in 5 (white, prior cancer, other ESKD).  相似文献   
19.
Two adult patients with the diagnosis of gastric lymphoma who developed adenocarcinoma of the stomach 8 years after the treatment are presented. Both patients were treated by subtotal gastrectomy followed by irradiation of 4,000–4,500 cGy to the epigastric region and six courses of chemotherapy (vincristine, cyclophosphamide, prednisolone). In our review of the literature, 16 cases of gastric adenocarcinoma following the treatment of gastric lymphoma were found and listed with details. The factors influencing the development of this secondary carcinoma, mainly those treatment related are discussed. The possible role of both radiotherapy and chemotherapy in shortening the latent period for the development of stump carcinoma is emphasized. © 1993 Wiley-Liss, Inc.  相似文献   
20.
Summary Cerebral primitive neuro-ectodermal tumour (PNET) occurring as a second primary malignancy in childhood is exceedingly rare. We present a 7-year-old boy who developed a proven supratentorial PNET five years after enucleation and radio-/chemotherapy for a sporadic, unilateral retinoblastoma with optic nerve invasion. The association with this malignant eye disease as well as the effect of irradiation and multi-agent chemotherapy on second tumour induction are evaluated.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号